A New Technique For Detecting And Dealing On The Void Of The Vault Behind The Final Lining Of Highway Tunnel

In the construction of two lining methods,the cavity behind the lining of the lining is a common phenomenon.In order to know the stress state of the lining of the two lining cavity and to improve the treatment method of the two lining arch at the same time.In Gansu Dingxi a tunnel,highway tunnel lining vault behind the void,based on the summary of previous research results,through the ANSYS numerical analysis on lining under different working conditions appear behind the void,the axial force,studied two masonry structure under various conditions of shear and bending moment is proposed;a new type of tunnel lining behind two crown grouting construction method,expounds the characteristics of this new method,the principle,material and equipment,quality control,safety control and environmental protection measures.The specific research conclusions are as follows:Stress characteristics of two liners under the two lining of tunnel:(1)The tunnel lining secondary voids affect the stress and deformation of the lining structure.With the increasing of the void range behind the secondary lining vault from 0 ° to 60 °,the secondary lining arch moment,Shear force,axial force and deformation gradually increased.(2)Under the condition of the empty hole of the secondary lining vault,the deformed state of the lining shows that the vault is pressed upward,the arch waist is pressed inwardly on both sides,the arch feet on both sides are pressed outward,and the inverted arch is pushed upwards Pressure of the trend.(3)According to the calculation results of six kinds of vault cavities,six typical characteristic points of vault,arch waist,side wall,inversion arch and inverted arch center can be drawn: vault roof and arch waist of lining structure Part of the larger impact,and with the gradual expansion of the hole range,the greater the impact.However,the influence on the structure of the side wall,overpass transitional section and upturned arch center is relatively small.Characteristics of construction method of vault grouting behind two lining of new tunnel:(1)Compared with the conventional filling grouting technique,the grouting process can be greatly reduced and the construction period is shortened.(2)The grouting method is adopted to carry out the grouting of the whole length of the vault,and the grouting is uniform without any omission,and the grouting effect is good.Grouting is completed before the two lining concrete reaches the initial setting,the grouting material and concrete lining materials without obvious interface,to ensure the effect of grouting under the premise of improving the strength of lining structure.(3)Because of the method,using two internal lining embedded at the same time,it is immediately after the two lining pouring is completed,the whole process without damage to the lining,no traces of lining,to ensure the quality of lining structure.(4)The method uses vault pre embedding grouting,symmetrical grouting for the lining vault problem,and saves a great deal of grouting material while guaranteeing grouting effect.(5)The method of grouting will be carried out immediately after the completion of the two lining concrete pouring,without the need of grouting at the later stage.The whole process is simple and time saving and labor saving,and a great deal of labor cost is saved.